Remember back in the 1990s when otherwise intelligent people would look to the scientific literature and say, “Those guys must be right. They used a computer model.”
A computer! How could they be wrong?
Yet once computers became ubiquitous, once they turned into mere “lifestyle” statements, once we started carrying the things everywhere in our pockets, this kind of talk died out. Results were no longer deemed extra-special-shiny just because they were formed inside a computer. Traditional notions of evidentiary goodness reasserted themselves, including the knowledge that computers only do what they’re told.
But when a result is based on a mathematical model—well! Just look at all those equations! Colorful graphs, too! We look at a paper written by mathematicians and think, “Anybody smart enough to go on and on about “dimensionless parameters” and “optimal depletion factors” must know what they’re talking about.” Right?
No, of course not.
All you need to understand about mathematical modeling is this: equations can be as error-free as Aristotelian syllogisms; nary a decimal out of place, but that does not imply that the use to which the equations are put is valid, or even sensible. Applying math to real life is not a mathematical operation, but a human act of interpretation.
For example, here is a perfectly respectable equation: y = x. We fill in numbers on the right-hand side and “solve” for numbers on the left-hand side. Simple. But what if I were to tell you—and recall I have a PhD in the subject from an Ivy League university—that “x” stands for Inequality and “y” for Distress, one an intolerably fuzzy notion and the other a raw emotion, and both scarcely measurable quantities. Would you be satisfied if I insisted that my mathematical model proved that distress causes inequality?
You might, if you had a stake in a political ideology which insisted on the relationship. And then you might not if you realized that quantifying such complex intricate inchoate ideas into two arbitrary numbers was next to impossible.
Does anybody create these kinds of model? Do they offer trivial equations with unquantifiable entities which purport to demonstrate, say, how entire civilizations might collapse?
Yes, of course.
X = The end of the world
NASA in its wisdom, through the grant “NNX12AD03A”, which it now publicly regrets issuing, funded the study, “Human and Nature Dynamics (HANDY): Modeling Inequality and Use of Resources in the Collapse or Sustainability of Societies” by Safa Motesharrei, Jorge Rivas, and Eugenia Kalnay, which will appear in the journal Ecological Economics.
The authors note that Rome is no longer with us, neither the Han Dynasty (though many Chinese might dispute this). And since these, and other civil societies such as the Aztec Empire, Carthage, East Germany, the Yugoslavia and many more, disappeared because of some cause, it makes sense to look for this cause.
Scholars are divided on why Rome collapsed, but a not unpopular answer is decadence coupled with an over-extended military, the rise of Christianity, and one or two other matters. Few would say a lack of food. Carthage had the bad habit of killing her newborns (good thing we don’t do this). The Aztec Empire let its population age a while before large numbers of them were sacrificed. (It was only later that science realized wholesale slaughter of one’s residents tends to cause demographic decline.)
Anyway, the authors note that “cultural decline and social decadence, popular uprisings, and civil wars” can cause or contribute to societal collapse. But none of these have to do with the environment, our modern obsession. So the authors ignored all possible causes except the environmental in “a simple model, not intended to describe actual individual cases, but rather to provide a general framework that allows carrying out ‘thought experiments’ for the phenomenon of collapse and to test changes that would avoid it.” They call this curiosity the “Human And Nature DYnamics (HANDY)” model.
It’s based on standard predator-prey models which work like this: a population of wolves eat the locally available deer, whose population necessarily declines, perhaps to the point where some wolves starve, decreasing their population; the concomitant reduced predation allows the deer to rebound, which gives the opportunity for more hot dinners for the wolves, which begins the cycle anew.
HANDY swaps the wolves for human beings and the deer for “Nature.” Just how people prey on Nature is not too clear, especially since people are part of Nature. This difficulty is ignored. HANDY introduces a twist which allows mankind to accumulate Nature for future use, a surplus which the model calls “wealth”. This would be like the wolves discovering how to make and store venison jerky.
About that wealth: “Empirically, however, this accumulated surplus is not evenly distributed throughout society, but rather has been controlled by an elite. The mass of the population, while producing the wealth, is only allocated a small portion of it by elites, usually at or just above subsistence levels.” Some wolves are more equal than other wolves.
Some humans do eat less than others, but this is a culture-relative measure. For instance, “poor” people (what the authors call “Commoners”) in the USA have much higher obesity rates than the “rich” (“Elites”). In medicine-speak, being a Commoner is a “risk factor” for obesity. What do the authors say to this clear objection?
They say this, the HANDY model. The claim is that culture’s fortunes are folded into these four simple equations.
The dots over the letters mean the thing represented by the letter changes over time. The names are: xC = the number of Commoners, xE = the number of Elites, y = the amount of Natural Resources, and w = Wealth. The latter two are expressed in units of “eco-Dollars”, a fictional entity which isn’t well described and doesn’t appear to map to any real thing.
The C’s are functions of w, xC, and xE, and the various Greek letters on the right-hand side allow the model to be tuned to give results the authors hope to see. Being able to put numbers to all these unquantifiable entities is what makes it Science.
The authors fiddled with the parameters to tell three stories: (1) The first of an Egalitarian society, one with no Elites, and therefore necessarily meeting the goal of Equality (where all have the same number of “eco-Dollars”); (2) An Equitable society, one with Elites, but where all are Equal; (3) An Unequal society, one with Elites and Commoners and imperfect Equality (where Elites have more “eco-Dollars” than Commoners).
Now without knowing the solution to the equations (which are easy to come by), and not knowing the values of all the tweakable parameters, just you take a guess which of these three scenarios reached Sustainability and which led to inevitable Collapses.
Under the Unequal society “collapse is difficult to avoid”, because why? Because “Elites eventually consume too much, resulting in a famine among Commoners that eventually causes the collapse of society.” But notice the confusion: eco-Dollars have somehow been transformed into food. But man does not live on bread alone. He also needs energy and shelter. So if eco-dollars are proxies for food, then where in the model are these other necessary quantities?
Particularly absent is the idea that only in a society which admits Elites can there be technological progress (what else is a writer of scientific papers but an Elite?). Consider how much food production has swelled over the last century as the discoveries made by Elites are implemented to the benefit of Commoners. Nature, in this sense, is not static as the model assumes.
But as already noted, in Western culture the opposite of the HANDY model has been observed. Elites, skipping over the precise meaning of “eco-dollars”, eat fewer calories than Commoners. They breed less, too. Having access to more Nature strangely means less food consumption and fewer humans. Think of Japan.
And in non-Western cultures, many of which are more Egalitarian relative to the West, there are good arguments that the meddling of Western Elites is what causes some famines, many of which are artificial owing to local (and global) politics.
Yet there is no notion of politics, and no mechanisms for the more important senses of cultural change (such as population-reducing war, disease, abortion and contraception use) in HANDY, and no idea that, as happens in reality, Commoners become Elites and vice versa. There is no real-life strict dichotomy between an Elite and Commoner. And new forms of wealth and ways of increasing Nature’s bounty are often unanticipated.
The HANDY model says Unequal societies must collapse. But which societies, say over the last century, in reality gave up their ghosts? We must ignore those that collapsed because of war (such as the Austro-Hungarian Empire, Cambodia) or politics (e.g. Rhodesia, Czechoslovakia) because HANDY is silent on these important subjects. The remaining collapsees were those societies which were Egalitarian (e.g. the Soviet Union, Cambodia again?). And how many collapsed solely because of the non-Egalitarian use of “eco-Dollars”? It’s hard to make a case that any did. Ireland is still with us. There were large famines in, say, Uganda, but the culture is still extant and the famines were in large part caused by war.
I don’t mean this to be a complete history, but as in our “y = x” model, saying the symbols mimic real life does not make it so, especially when the model makes predictions opposite to reality. HANDY has no applicability to human cultural change. But it’s a matter of interest to see who is most anxious to believe the model.
The authors, whose faith in their model is strong, are ready with their political suggestions, which include recommending “major reductions in inequality and population growth rates”. The Guardian eagerly agrees and says “The NASA-funded HANDY model offers a highly credible wake-up call to governments, corporations and business—and consumers—to recognise that ‘business as usual’ cannot be sustained, and that policy and structural changes are required immediately.”
Once again, the triumph of theory over reality.